If you don’t have an electric screwdriver, your tool kit is missing a compact and convenient component. These tools have hundreds of uses, from assembling furniture to adjusting the kids’ bikes to installing electrical sockets to mending home appliances.

With the huge variety of different fasteners now in use, a couple of old screwdrivers and a set of hex keys are no longer enough. But with a good electric screwdriver and a selection of bits, you’ve got an enormous number of DIY and trade tasks covered.

One of the big decisions when choosing one of these tools is physical size. Larger models produce a lot of power, but sometimes you just want the simplicity of something that fits in the palm of your hand. If you’d like to learn more about electric screwdrivers, including other important features to look for and the price ranges you can expect to see while shopping, read on.

Some people use a cordless drill/driver for screwdriving tasks, and it’s certainly a powerful and versatile tool. The drawback is its bulk. It isn’t a small, lightweight gadget you can drop in a pocket or keep in a kitchen drawer. But an electric screwdriver is precisely that. It’s easy to use, easy to store, yet powerful enough for all those different screws you come across, whether at home or in the workplace.

Volts: There are two output options when choosing an electric screwdriver: 3.6 volt or 7.2 volt. Recently, there’s been some confusion with the introduction of 4-volt and 8-volt models, but they aren’t actually more powerful. Let’s explain.

All motors produce a power surge at startup — a voltage spike. They return to the normal (nominal) voltage in fractions of a second. Thus an 8-volt electric screwdriver actually runs at 7.2 volts nominal, and a 4-volt electric screwdriver runs at 3.6 volts. Some manufacturers choose to quote the higher figure. It’s not wrong; it’s just marketing!

In real terms, the big difference is between 7.2-volt and 3.6-volt screwdrivers. The 3.6-volt screwdrivers are almost always notably more compact, exactly the kind of thing you’d keep in a kitchen drawer for occasional DIY tasks. For heavy-duty jobs you want a 7.2-volt electric screwdriver.

Milliampere-hours: The other consideration for both types of electric screwdriver is the ampere-hour (Ah) rating, sometimes just called amps. If voltage is out-and-out power, then ampere-hours indicate how long that performance can be delivered consistently. Electric screwdrivers are often rated by milliampere-hours (mAh), and, basically, the higher the number the better. A 2,000 mAh model will outperform a 1,300 mAh model by some margin. If you’re comparing similar models, this can make a big difference.

Battery: The 3.6-volt screwdrivers usually have built-in battery, which is charged in place, often via a USB cable. While charging from a mains socket is fastest, you can also use a laptop, a port in your vehicle, or any number of alternatives.

Many 7.2-volt models use a separate charger. This is an advantage for the professional if you have two batteries. You can carry on working while one screwdriver recharges. Charging times can vary from 60 minutes to several hours, so it’s an important consideration for some.

Models with these slide-out batteries are often sold as bare tools, meaning the battery and charger are extra. With some power tools, this allows you to save money by sharing batteries, but few electric screwdriver batteries are interchangeable, so you need to compare prices carefully.

Push drive: The most recent development in electric screwdriver technology is push drive or gyroscopic. Although the mechanisms differ, they can increase or decrease power, run clockwise or counterclockwise, solely by reacting to user input.

Clutch: A clutch is useful to prevent overtightening of screws. These are particularly important on the more powerful 7.2-volt models, which produce enough torque to cause damage if you aren’t careful.

Handle: Some electric screwdrivers have a handle that can be set in two or more positions for user comfort.

Lights: LED lights are useful if you’re working in dark corners. Battery charge indicators are offered on some tools.

Extras: It’s not uncommon to find angled heads, flexible shafts ,and other swappable extras that can extend the use of your electric screwdriver. However, if you’re looking at drill and saw attachments, it’s important to understand the limitations of these tools. Sometimes you need to go for the full-size alternative.

Bit storage: Some electric screwdrivers have onboard bit storage, which can be handy if you’re regularly changing from one to another.

Inexpensive: You can pick up a cheap, basic 3.6-volt cordless screwdriver to take care of all those little DY jobs around the home for between $15 and $20. Even at that price, there’s plenty of choice.

Mid-range: If you want a more powerful 7.2-volt model, you’ll need to spend from $30 to $60. The number of extras will have quite a lot of impact on the price. There are still a lot of 3.6-volt models in this range, usually fairly comprehensive sets from the better-known brands.

Expensive: Professional-grade electric screwdrivers can cost $100 or more, which seems like a lot when you consider what you can get for half that. However, if it’s a tool you rely on all day, every day, then things like a spare battery are important. For tradespeople, these tools are worth the investment.

• Use the right type of bit. There are dozens of fasteners available, and some are quite similar, but minor differences can mean the bit will “cam out” — it won’t stay in position when driving or loosening.
• Use the right size bit. Slotted screwdrivers, in particular, will twist out and damage the head. All bits should fit snugly in the screwhead recess regardless of type. You can feel when it’s positively engaged. If it isn’t, change it.
• Buy quality. Cheap bits wear out quickly. Some gold-colored bits are made of titanium nitride (TiN), which is very hard and durable, but be careful. Some bits are just painted gold!
• Start slowly. Support the screw while it engages, then increase speed once it’s running true. If the screwhead looks damaged, throw the screw away and use a new one. Trying to undo a damaged screw later it can be a nightmare! And remember, when unscrewing, you still need to apply a little pressure to the screwdriver to keep the bit properly seated.
• Keep it charged. Don’t struggle with an electric screwdriver that’s running low on charge. It just gets frustrating. There’s probably something else you can do while it recharges, and it will be ready to do the job properly when you come back.

If you work on electronics, the Nanch Small Precision Screwdriver Set is a smart and comprehensive kit with 22 bits, extending shaft, and magnetic tip, so you don’t drop those tiny screws. The NoCry Cordless Electric Screwdriver may not be from a well-known brand, but it has plenty of satisfied users, which isn’t surprising when you check the specifications, including 7.2 volts, 30 bits, and a flexible extension, all at a very competitive price. The Skil 2354-12 iXO Power Screwdriver is another compact 4-volt device. What sets it apart is the cutter attachment that will cut through card, carpet, and even chicken wire. It’s a neat little extra to add to your tool kit.

Q. What’s the difference between a standard electric screwdriver and a “precision” model?
A. The standard model is for everyday screwdriving, like you might find on cabinet pulls, plugs, bicycles, all around the home. Precision electric screwdrivers are small, pen-like devices used for the kinds of screws you find in glasses, cameras, and circuit boards.

Q. Do I need to buy screwdriver bits as well?
A. It depends on the electric screwdriver model and what you want to do. Phillips-head and slotted-head bits cover most jobs and are invariably provided. However, there always seems to be another fixing on the market — square drive, five-point, Torx — so if you’re doing a lot of DIY, having a comprehensive set of bits is a good idea. Some are provided with the screwdriver. If you’re just buying the driver on its own, a boxed set is a relatively cheap addition.

Q. Do I need to buy separate lithium-ion batteries for a cordless screwdriver?
A. Not often. The difference between a drill/driver and many dedicated electric screwdrivers is that the battery for the latter is often permanently built in and charged via cable in situ. You can try to work while it charges, if the cable will reach, though performance is likely to be considerably reduced. We suggest waiting until it has recharged.